When you are a fundamental investor evaluating stocks, you don’t need to know any advanced math or statistics. What you need is just a strong grasp of working with numbers and good mental math skills. You should also have a solid grasp of introductory/intermediate statistics and some basic linear (matrix) algebra, with the latter only needed if you want to get deeper into factors and risk, which many would argue you don’t even need to know. It is quite surprising to see how many investors aren’t fluent with numbers enough to work with comps and growth rates.